Elisabeth Sladen returned for a new generation of fans in the "The Sarah Jane Adventures."

The actress originally starred in "Doctor Who" for three years in the 1970s. Here she is alongside Tom Baker.

"Doctor Who" star Elisabeth Sladen, who was also in spin-off series "The Sarah Jane Adventures", has passed away at 63.

Sladen appeared as Doctor Who assistant Sarah Jane Smith in the BBC television sci-fi series between 1973 and 1976, opposite Jon Pertwee and Tom Baker.

The Liverpool-born actress appeared in four series from 2007 of The Sarah Jane Adventures on children's channel CBBC.

Sladen had been battling cancer for some time and leaves actor husband Brian Miller and daughter Sadie.

Theatre work

A BBC spokesman said: "It is with much sadness that we can announce Elisabeth Sladen, the much-loved actress best known for her role as Sarah Jane Smith in Doctor Who and CBBC's The Sarah Jane Adventures, passed away this morning."

Sladen first appeared as Sarah Jane alongside the third Doctor, Jon Pertwee, and stayed for three-and-a-half seasons, also working with the fourth Doctor, Tom Baker.

Her character, a journalist, was renowned for being inquisitive and stronger than some of the Doctor's other assistants.

After her time in the Tardis, Sladen returned to her native Liverpool where she worked in theatre.

She returned to the role on several occasions over the years and was given her own spin-off series on CBBC in 2007, in which she appeared with the most recent two Doctors, David Tennant and Matt Smith.

In 2006, ahead of rejoining Doctor Who, Sladen said of the programme: "I think it has lovely layers and I'd defend the programme to anyone.

"I'm very emotionally part of that programme and I think a lot of the people who worked on it are. You used to love going to work every day."

'Brilliant presence'

CBBC controller Damian Kavanagh said he was "deeply saddened and shocked by the news of Lis's untimely death".

"Lis brought joy, excitement and a sense of wonder to her many fans in her role as Sarah Jane Smith. She was adored by our young audience and I know all of them will miss her as much as I will," he said.

Russell T Davies, the creator of The Sarah Jane Adventures, said: "I absolutely loved Lis. She was funny and cheeky and clever and just simply wonderful. The universe was lucky to have Sarah Jane Smith, the world was lucky to have Lis."

Keith Jones, the director of BBC Wales, which makes The Sarah Jane Adventures, said: "The Sarah Jane Adventures has been one of the most successful children's programmes on television in recent years - and without Elisabeth Sladen it would not have happened.

"A brilliant presence on screen and on set, she brought the excitement and energy of the Doctor Who family of programmes, of which we are very proud at BBC Wales, to a whole new generation. She will be missed by all at BBC Wales who worked with her."

Sladen's agent Roger Carey described her as a "dear friend".

He said: "She was so positive about life and her natural energy was intoxicating. She couldn't believe her luck when her career was resurrected in her own series."

Doctor Who executive producer Steven Moffat said she had been a "ferociously talented actress".